LARGE FORM DIGITAL FLAT PANELS

The inevitability of it should be obvious. As prices drop further and further on LCD monitor tecnology, the availability of large size DFPs (Digital Flat Panel) has been on the rise. With market leaders such as Apple with their line of Cinema Display monitors, with native resolutions ranging from 1660 x 1050 up to 2560 x 1600, and Dell with their new 24 inch display, capable of 1920 x 1200 native resolution, becoming more and more popular, users are beginning to learn about DVI's limitations the hard way.

Although it is changing, almost every current 3D gaming card, including the high end cards, only supports Single Link TMDS. That means that there is almost no way to support these incredible new monitors without the use of some specialized video card that can support Dual Link TMDS.

SINGLE LINK DVI AND A DUAL LINK DVI

The DVI spec transmits data using the transition minimized differential signaling (TMDS) protocol. The DVI spec calls for each DVI output to have at least one TMDS “link” consisting of three data channels (RGB) and one control channel. The maximum speed at which a single TMDS link may operate at is 165MHz, offering 1.65Gbps of bandwidth. In real world terms, this means a single TMDS link can drive a display at up to 1600 x 1200 at 60 Hz. For a dual link TMDS, which is in essence two TMDS links bonded together, can display at resolutions up to 2048 x 1536 - and is the connector of choice for users of extremely large digital flat panels.

Single Link - 1600 x 1200 Max Digital Resolution

Dual Link - 2048 x 1536 Max Digital Resolution

Notice that Dual Link cables and cards use 6 more pins than are found on the Single Link connectors

But don't take this as the absolute truth - many single link video cards and devices still use the full dual link connector. So it is always best to check with your video card manufacturer to see what type of DVI support your hardware is capable of.